What is a Three-wire RTD ?
A compromise between two-wire and four-wire RTD connections is the three-wire connection, which looks like this: In a three-wire RTD
rtd pt100 3 wire
Formula of 2 Wire RTD, 3 Wire RTD & 4 Wire RTD
2 Wire RTD : where Rpt is Resistance of RTD R2 is Resistance of first lead wire (Extension cable used